Shipping container



F. JOHNSTON SHIPPING CONTAINER Dec. 8, 1964 3 Sheets-Sheet 1 Filed April 23 1962 ATTORNEYS Dec. 8, 1964 F. JOHNSTON SHIPPING CONTAINER 3 Sheets-Sheet 2 Filed April 23 1962 FIG. 5

I I I n u I u I INVENTOR F r derick Johnsron E ATTORNEYS Dec. 8, 1964 Filed April 23 1962 F. JOHNSTON 3,

SHIPPING CONTAINER I 3 Sheets-Sheet 3 FIG.9

I NVENTOR Frederick Johnston PM W M BM M641 ATTORNEYS United States Patent Oflice 3,160,312 Patented Dec. 8, 1964 3,160,312 di-EEPlNG CONTABIER Frederick .iolnrston, Pittsburgh, Pa, assignor, by mesne assignments, to American Light Gaga Drum orporation, New York, N.Y., a corporation of New York Filed Apr. '23, 1%2, Ser. No. 139,357 7 Claims. Ci. 228-67) This invention relates to improvements in metal shipping containers, and more particularly to steel drums made of sheet metal, in which at least one head or end is secured to the shell in a permanent leakproof manner, and in which both headsor ends are advantageously so secured.

The invention includes improvements in light-weight, steel drums made of light gauge steel, which are leakproof and which have other advantages which enable them to be used to replace steel drums made of heavier gauge steel.

The invention also includes steel drums made of heavier gauge steel, which have advantages which enable them to be used to replace heavy gauge drums with reinforced chimes.

The most commonly used method of securing the sheet metal head or end of a drum to its sheet metal shell or cylindrical portion is by forming complementary radially outwardly extended flanges on the head and on the shell, assembling the head within the shell with the flanges in contact with each other, supporting this assembly on chucks, rotating the assembled head and shell and folding the flanges together by suitably grooved wheels progressively moving toward the axis of the shell, to form a chime known as a double seam. The infolding of the flanges is completed by compressing and compacting the folds of the double seam to the desired final form.

This conventional double seam on steel drums has numerous weaknesses which are well known to those skilled in the drum-fabricating industry and are well understood by various inspection agencies which find it necessary to prescribe rigid tests before approving double seamed drums for shipment on common carriers.

The primary purpose of forming a double seam is to produce a le'alproof joint to prevent leakage of the contents of the drum during shipping, handling or storage of the drum. But due to the fact that the metal of the double seam is only mechanically interlocked, the folds of the metal must remain in this intimate contact in order that the seam may remain leakproof. Any distortion of the chime, due to either a drop of the drum or other impact on the chime, is likely to induce a slight separation of the folds of the chime, resulting in a leak.

In the operation of forming the double scam, the seaming wheels are required to exert tremendous pressures in order to compact the folds of the seam, in the course of which the metal is severely bent upon itself and pinched. The great pressure frequently results in the formation of sharp edges, particularly at the top of the seam. This frequently results in the crushing and partial fracturing of the metaland the formation of incipient cracks in the metal of the seam, resulting in leaks in testing, shipping, storing, and normal handling of the filled drums.

Attempts have been made to overcome these objections to a double seam by the use of sealing compounds, by adding reinforcing metal bands around the double seamed chime, and also by welding the chime. The use of sealing compounds has its limitations and objections. The applicationof reinforcing metal bands involves an added expense and added operations. And the welding of the double seam only partially overcomesits deficiencies.

The present invention provides an improved metal container which avoids the formation of a double seam and provides instead a welded tubular chime of a special construction which overcomes the objections and deficiencies of the double seam and has special advantages in its method of production and in the resulting drum.

Among the objects of the invention are the following: to produce a chime for a metal drum which will be leakproof without any dependence upon the tightness of the infolding of the meeting head and shell flanges; to provide a chime in which the metal in the chime is not overstressed, pinched or fatigued to cause incipient fractures or cracks; to produce a chime which will not require a great crushing pressure in the formation of the chime, thus eliminating the requirements of heavy machinery and great power for its fabrication; to produce a chime which will not require a sealing compound toinsure a leakproof construction; to produce a chime whichwill be stronger in resisting distortion than the conventional double seam; to produce a chime which will not leak as a result of any distortion of the chime; to produce a chime which is tubular in conformation; to produce a chime which will successfully withstand the required 4-foot or 6-f00t drop test, striking upon concrete, when the fully filled drum is dropped on the chime striking on a concrete floor; to

produce a chime which will not open when subjected to the prescribed hydrostatic pressure tests-and will with stand hydrostatic pressures which produce stresses aproaching the ultimate strength of the sheet metal of which the drum is made; to produce a flange welded chime in which the mating head and shell flanges are so formed that the subsequent roll forming or curling of the welded flanges into a chime will not impose any shearing or tearing stresses on the weld or on the metal adjacent to the weld; to produce a chime which is formed with a substantially radially disposed stiffening strength member located interiorly of and intermediate the top and bottom of the chime, thus forming what may be termed a -honeycomb construction; and to produce a chime which is substantially larger than a double seam made of the same thickness of sheet metal.

In producing the drums with the new improved chimes, the shell or cylindrical portions of the drum and the head (which may be the top or die bottom end of the drum) are provided With outwardly extending flanges and are as sembied with the head within the shell, with the flanges in contact with each other and extending outwardly, and with the flange on the head extending outwardly beyond the flange on the shell. The flanges are then welded at a location which is away from the angles of the flanges and also away from the outer edges of the dan es, so that there will be outwardly projecting portions of both flanges beyond the weld and so that there will be suflicient metal for the forming of the end portion of thetnbular chime between the weld and the angles of the flanges. It will be understood that these angles of the flanges may also be referred to as curved sections joining the flanges to the walls of the drum shell and head respectively.

It is also important that the radius of the angle at the inner end of'the head flange is made smaller thanthe nesting radius of the shell flange. radii is made suiiicient so that the metal of the head radius will re-form to just snugly engage'the metal of the shell radius without developing any shearing actionbetween the head and shell metal.

With the head thus inserted in the shell, and with the flanges beyond the weld so formed or curled as to re-' inforce and strengthen or stiffen the resulting oval chime.

The welding of the flanges is advantageously carried The difference in these out by electric resistance welding. The flanges should be carefully .cleaned to present fresh surfaces before they are welded. While electric resistance welding is advant-ageously used, other types of welding may be used or other means of joining. the flanges with an integral union such as soldering, brazing or the use of suitable cements which give the equivalent of a fused union.

The location of the zone of welding or fusion of the flanges is important. It should be kept well clear of any point of possible impact and away from the point of wear or abrasion, to avoid or minimize danger of fracturing. The fusion zone or welded zone is advantageously located at about the center of the height of the curled oval chime.

As a result of. the forming of the flanges into an oval chime, the portion of the oval chime which supports the drum is away from the weld and has a rounded end portion in contrast with the sharp angle of a double seam.

The making of the steel drums with the new welded tubular chimes enables steel drums, e.g. of 55 gallons ca pacity, to be made of light gauge steel, such as 24-gauge steel, which will withstand the drop test and other tests for such drums. Single trip, light gauge steel drums can thus be'made which are suitable for replacing drums now made of heavier gauge metal.

With such light gauge drums, the head which forms the bottom of the drum is advantageously provided with a support, or formed with a portion of the head serving as a support, and extending to approximately the same level as the end of the chime, so that during shipment the drum will be supported'in part by the head and in part by the chime.

With such light gauge drums, made e.g. of 24-gauge steel, the shell or cylindrical portions of the drums are advantageously provided with three or more flat rolling hoops, which serve to strengthen or reinforce the shell portion of the drum.

Light gauge drums can thus be made of steel of less than ZO-gauge, e.g., ZZ-ga-uge or 24-gauge for 55-gallon drums, and an even thinner gauge of steel for 30-gallon drums.

Steel drums are also commonly made of heavier gauge steel, such as SS-gallon metal containers of 18, 16 or 14- gauge. With certain of the heavier gauge drums, the double seams are reinforced by reinforcing metal bands. This requires an added operation in the production of the drum, involving the addition to the double seam of a reinforcing chime hoop and subjecting it to the action of a curling wheel to complete the curling, compressing and compacting operation necessary to lock the reinforcing hoop securely over the conventional double seam chime.

The improved drums of the present invention, made of heavy gauge steel, with the welded tubular chimes, enable the use of such reinforcing chime hoops to be eliminated.

Steel shipping containers of heavy gauge steel made with the improved welded tubular chimes of the present invention are capable of withstanding all I.C.C. tests required of the drums currently produced from heavier gauge shell, head and bottom construction, and further reinforced with the costly heavy gauge chime reinforcing hoops.

p The invention will with the accompanying drawings, which illustrate in a somewhat conventional and diagrammatic manner, one form of drum embodying the invention and one method of making the drumwith the improved chimes, but it will be understood that the invention is not limited thereto.

Inthe accompanying drawings,

FIG- 1 is a perspective view of the shell or cylindrical portion of the drum before assembly, showing the reinforcing flat hoops and-flanges;

FIG. 2 shows one form of drum head or end before assembly, this form being that of the drum bottom illustrated in FIG. 9; r

FIG. 3 is an enlarged cross-section showing the welded flanges and the adjacent portions of the shell and drum head, before the formation of the tubular chime;

be further described in connectionoperation.

FIG. 4 is a similar sectional view showing the completed chime;

FIGS. 5 and 6 illustrate the first stage in the formation of the chime, FIG. 5 illustrating the position of the welded flanges on the chuck, and the first curling Wheel in position prior to its advance toward the rotating welded flanges, and FIG. 6 illustrating the position at the completionof the first curling operation;

FIGS. 7 and 8 illustrate the, second stage in the formation of the chime, FIG. 7.illustrating the position of the partially curled flanges on the chuck, and the second finishing curling wheel prior to its advance toward the partially curled flanges, and FIG. 8 illustrating the position of the parts at the completion of the curling operation; and

FIG. 9 shows one. form of finished drum with the tubular chimes at both ends.

In making the new drums, a shell or cylindrical portion 1, such as illustrated in FIG. 1, is provided with end flanges 2 and 3 and with flat rolling hoops 4. This figure illustrates the shell or cylindrical portion, made of e.g. 24-gauge steel with four flat reinforcing rolling hoops. Steel drums of 55 gallons capacity, and of heavier gauge steel, usually have two curved rolling hoops located at about a third of the length of the drum from each end.

FIG. 2 shows one form of drum head suitable for use at the bottom of thedrum. This drum head 5 has 21 peripheral flange 6 which is wider (longer in cross-section) than the flanges 2 and 3 on the drum shell. It has a cylindrical wall portion 7 which fits or telescopes into the cylindrical portion of the drum shell, and it has portions 8 whichare bent downwardly to a level which is the same as or which approximates the bottom'ot the drum chime.

' A series of three inwardly extending annular projections 9, it and 11 are located between the portions 8 of the drum head. The centraliportion of the drum head member 5 including the portions 8 is joined to its cylindrical wall portion 7 by a section 7a having a large radius as shown in FIGS. 3 and 4-. i

From FIG. 3, it will be seen that the radius 13 of the angle of the head flange is smaller than the radius 12 of the shell flange. The difference in these radii is sufficient so that the metal of the head radius will snugly engage the middle of the shell radius without developing any shearing strain between the head and the shell metal during the chime formation.

The flanges are shown in FIG. 3 and FIG. 5 as at right angles to the axis of the drum. If .the flanges are Welded in an angular posit-ion which is other. than at right angles to the shell axis, the flanges should be bent or deflected to a position at right angles to the axis of the drum, which is the position in which they are. shown in FIG. 5.

The curling operation by which the flanges are converted into the final tubular chime isa two-stage operation, with the first stage illustrated in FIGS. 5 and 6 and the second stage in FIGS. 7 and 8.

In FIGS.'5 and;6, the first curling wheel 20 has a circular groove 21, and the chuck 22 supports the drum shell and head.

FIG. 5 illustrates the position of the welded flanges on the chuck and the location of the first curling wheel in position prior to its advance toward the rotating welded flanges.

FIG. 6 illustrates the position of the first curling wheel in its preferred position at the completion of the first curling operation, and accordingly this view also shows the preferred configuration of the flanges at the completion ofthe first step of the chime curling.

FIGS. 7 and 8 illustrate the second stage of the curling 'Ihe curling wheel 23 has the circular groove 24 therein, and the chuck 25 supports the drum during this latter operation.

7 FIG. 7 illustrates the position of the partially curled flanges on the chuck and the second or finishing curling wheel in position prior to its advance toward the partially curled flanges. I

FIG. 8 illustrates the position of the parts at the completion of the curling operation, showing the second wheel in the final position, and also illustrating the conformation of the curled chime produced by the advance of the finishing wheel toward the partially curled flanges.

From FIGS. 5 and 6, it will be seen that the first step of the curlin of the flanges bends the outer portion 16 of the head flange 6'inwardly to a tubular or rounded shape, with the end or edge of the flange in contact with or adjacent the welded portion 14. It will also be seen that in the second step of the process, illustrated in FIGS. 7 and 8, this inturned or tubular portion of the outer portion 16 of the head flange is retained in a somewhat modifled form, and that both flanges are formed into an oval chime of tubular double walled cross-section, as illustrated in FIGS. 4 and 8.

In the oval chime, the outer edge portion 15 of the shell flange is bent inwardly and ends substantially at right angles in close proximity to the shellnear the bottom of the chime as shown in FIG. 8, or near the side of the chime in FIG. 4, and serves to reinforce this portion or" the chime. The outer portion 16 of the head flange encloses the end (edge portion 15) of the drum flange and is turned back so that outer portion 16 has a portion resting on the shell and with the end or edge extending outwardly to the Weld 14 (which is located near the middle of the outer portion of the chime), thus forming a transverse reinforcing stiffener to strengthen the curl against an inward thrust such as imposed by a diagonal drop of the drum on the chime.

This inturning of the flanges results in the formation of a'chirne of tubular cross-section, with an inner tubular portion formed by the inturning of the edge of the flange outer portion 16. The weld is at about the middle of the chime and away from the end portion of the chime.

The oval chime is thus one in which the inturning of the outer portions of the flanges, beyond the weld, serves to strengthen and reinforce the chime.

In a double scam, the radial thickness of the seam is never more than the thickness of the five layers of the metal of which the seam is formed; and in practice this scam thickness may be less, due to the tremendous seaming pressures applied to compact the folds of the metal.

In contrast with such a structure and thickness, the tubular chime of the present invention is approximately twice as thick as the conventional double seam made from the same thickness of metal, and also, as distinguished from a double seam, the oval chime of the present invention has a relatively large, nicely rounded radius at the bottom of the chime, as indicated at 18 in FIG. 4, and a smaller, but clearly rounded radius 19 at the top of the curled chime. It will also be seen that the outer portions of the flanges beyond the weld are curled and formed into reinforcing members, with the outer portion 15 of the shell flange extending inwardly, and the outer portion 16 of the head flange extending first inwardly and then outwardly.

One test for drums with conventionally formed double seams is the prescribed four-foot drop test, for light gauge drums, and a six-foot drop test for heavy gauge drums, upon a concrete floor. The rounded or tubular curled chimes of the present invention form a rounded contour where the drum is dropped on the chime, which is stronger than the conventionally formed double seam using the same amount of material.

The location of the weld away from the end of the chime and the provision of a rounded portion of the chime between the weld and the cylindrical portion of the drum protects the drum both during the drop test and also from wear and friction when the drums are dragged along the floor.

The drum illustrated is a light gauge steel drum of e.g. 24-gauge steel. With this thickness of metal, the circular grooves 21 of the first stage of the curling process was j nds of an inch wide, and the groove 24 in the second stage of the curling process, nds of an inch wide. The height of the chime was approximately 0.336 inch, and the thickness of the chime approximately .254 inch. These chimes extend outwardly about twice the distance of a double seam of the same thickness'of metal, but do not extend out as far as the rolling hoops 4.

It will be evident that, with drums of heavier gauge steel, there will be a corresponding change in the grooves of the forming wheels and in the size of the final tubular chime.

The drum ends or heads can also be varied with the gauge of the metal used. With heavy gauge drums, the drum heads or ends may not need any special support, and the ordinary curved heads or ends can be used.

With light gauge drums such as illustrated in FIG. 9, the head or end at the bottom of the drum has supporting portions 8 formed therein, extending to or approximately to the level of the ends of the chimes, so that, when the drums are filled with liquid, these portions of the drum bottom will be supported by the same support as the chimes. This type of drum end has the advantage of overcoming vibration and resulting weakening, which might occur if the drum bottom of thin metal was not properly supported. i

The drum head 26 at the top of the drum of FIG. 9 has two filling openings 27 and 28 and has the central and main portion of the drum head extending upwardly to a level approximating that of the top of the drum chimes, so that, if the drum should be inverted, this portion of the V drum head would serve to support the contents of the I drum in much the same manner as the drum heads shown at the bottom of the drum in FIG. 9.

I claim:

1. A steel drum made up of a shell having a cylindrical wall with a head member at each end having a cylindrical wall portion telescoped within the end portion of the sheel, the head' and shell members having flanges joined by curved sections to their respective wall portions, the shell and head member flanges being continuously welded together at a location which is away from the edges of the flanges and also away from the curved sections of the flanges, said head and shell flanges at each end of the drum being formed into a tubular chime of double-walled hollow cross-section having the welded portion near the middle of the outer portion of the chime, the flange on the head member being longer in cross-section than the shell flange, and the portion of said head flange beyond the weld being curled into contact with thesurface of the shell with the edge portion of the flange extending outwardly toward the central portion of the tubular chime. r

2. A steel drum as defined in claim 1 wherein said edge portion of the head flange extends outwardly and engages the weld at the central portion of the tubular chime.

3. A steel drum asdefined in claim 1 wherein the portion of the shell flange beyond the weld is curled in wardly in contact with the inner surface of the portion of the head flange which is in contact with the shell.

4. A steel drum as defined in claim 1 made of light gauge steel and having a head member at the bottom of the drum comprising a central portionwhich is joined to its cylindrical wall portion by means of a section having a large radius, the central portion of said bottom head member extending downwardly to approximately the level of the bottom of the drum chime.

5. A heavy gauge steel drum as defined in claim 1 made of heavy gauge steel of l8-gauge or heavier.

6. A steel drum made up of a shell having a cylindrical wall with a head member at each end having a cylindrical wall portion telescoped within the end portion of the shell, the head and shell members having flanges joined by curved sections to their respective Wall portions, the shell and head member flanges being bonded together along a circular ribbon-like region disposed away from the edges of the flanges and also away from the curved sectionsof the flanges and extending continuously aroundt-heflanges, said head and shell flanges at each end of the drum being formed into a tubular chime of double Wall hollow cross-section having the circular ribbon-like bonded region disposed near the middle of the outer portion of the tubular chime, the flange on the head member being longer than the shell flange, and the outer portion of the head flange beyond the bonded region being curled into contact with the surface of the shell with the edge portion of the flange extending outwardly towards the central portion of the tubular chime.

7. A steel drum as defined in claim 6 wherein said edge portion of the head flange extends outwardly and engages the central portion of the tubular chime.

Knapp 220-67 Graham 22067 McClary 113--120 McClary 113121 OBrien 22067 Fycker et al 22067 Brookson 22067 FOREIGN PATENTS 15 THERON E. CONDON, Primary Examiner. 

1. A STEEL DRUM MADE UP OF A SHELL HAVING A CYLINDRICAL WALL WITH A HEAD MEMBER AT EACH END HAVING A CYLINDRICAL WALL PORTION TELESCOPED WITHIN THE END PORTION OF THE SHEEL, THE HEAD AND SHELL MEMBERS HAVING FLANGES JOINED BY CURVED SECTIONS TO THEIR RESPECTIVE WALL PORTIONS, THE SHELL AND HEAD MEMBER FLANGES BEING CONTINUOUSLY WELDED TOGETHER AT A LOCATION WHICH IS AWAY FROM THE EDGES OF THE FLANGES AND ALSO AWAY FROM THE CURVED SECTIONS OF THE FLANGES, SAID HEAD AND SHELL FLANGES AT EACH END OF THE DRUM BEING FORMED INTO A TUBULAR CHIME OF DOUBLE-WALLED HOLLOW CROSS-SECTION HAVING THE WELDED PORTION NEAR THE MIDDLE OF THE OUTER PORTION OF THE CHIME, THE FLANGE ON THE HEAD MEMBER BEING LONGER IN CROSS-SECTION THAN THE SHELL FLANGE, AND THE PORTION OF SAID HEAD FLANGE BEYOND THE WELD BEING CURLED INTO CONTACT WITH THE SURFACE OF THE SHELL WITH THE EDGE PORTION OF THE FLANGE EXTENDING OUTWARDLY TOWARD THE CENTRAL PORTION OF THE TUBULAR CHIME. 